am 088521ef: Merge "Allow system images larger than 2GiB, pt. 2"

  finally:

    print "cleaning up..."

    # http://b/18015246

    # See common.py for context.  zipfile also refers to ZIP64_LIMIT during

    # close() when it writes out the central directory.

    saved_zip64_limit = zipfile.ZIP64_LIMIT

    zipfile.ZIP64_LIMIT = (1 << 32) - 1

    output_zip.close()

    zipfile.ZIP64_LIMIT = saved_zip64_limit

    shutil.rmtree(OPTIONS.input_tmp)

  print "done."